The Criollo is a hardy horse with a brawny and strong body with a broad chest and well-sprung ribs. They have sloping strong shoulders with muscular necks, short and strong legs with good bone structure and resistant joints, low-set hocks and sound hard feet. The medium to large size long-muzzled head has a straight or slightly convex profile with wide-set eyes. The croup is sloping, the haunches well-muscled, and the back, short with a strong loin.

The criollo is tractable, intelligent, willing and sensible. Criollo horses average 14.3 hands high, being the maximum height for stallions and geldings of 14 to 15 hands high. The difference between the maximum and minimum height for mares is approximately 2 cm (one inch). The line-backed dun is the most popular color, but the breed may also come in bay, brown, black, chestnut, grullo, buckskin, palomino, blue or strawberry roan, gray and overo colors. The breed is famous for their endurance capabilities and ability to live in harsh conditions, as their homeland has both extreme heat and cold weather. They are frugal eaters, thriving on little grass. They have good resistance to disease and are long-lived horses.

More Info: en.wikipedia.org